This stuff is awesome. It has made my nails a lot stronger. And as someone else mentioned, it keeps dark colors from staining your nails. I have found it slightly harder applying the first coat of polish over this, but not enough that I would stop using it. If you purchase this in a salon or store it can be pricey. It is cheaper to buy online...I buy from 8ty8beauty & have had nothing but pleasant experiences ordering from them.